bitwise_string_ops - Bitwise operators for the String class
gem install kingpong-bitwise_string_ops --source http://gems.github.com # in your code: require 'rubygems' require 'bitwise_string_ops' # or in Rails' environment.rb: gem "kingpong-bitwise_string_ops", :lib => "bitwise_string_ops"
This gem extends the String class to include the bitwise operators ‘|’ (OR), ‘&’ (AND), ‘^’ (XOR) and ‘~’ (NOT). The semantics are as close to Perl’s bitwise string operators as possible (see “perldoc perlop”).
The operation is applied to each successive byte (not necessarily character) in the source strings in parallel. For example, the result of “AB” & “CD” is (“A” & “C”) + (“B” & “D”).
If the operands to a binary bitwise op are strings of different sizes, | and ^ ops act as though the shorter operand had additional zero bits on the right, while the & op acts as though the longer operand were truncated to the length of the shorter. The granularity for such extension or truncation is one or more bytes. [source: perldoc perlop]
For strings of the same length, nothing unexpected:
"r b " ^ " u y" # "RUBY" # # 01110010 00100000 01100010 00100000 # "r b " # ^ 00100000 01110101 00100000 01111001 # " u y" # ======== ======== ======== ======== # 01010010 01010101 01000010 01011001 # "RUBY"
OR operation expands to the larger of the two strings:
"RU" | " by" # "ruby" # # 01010010 01010101 # "RU" # | 00100000 00100000 01100010 01111001 # " by" # ======== ======== ======== ======== # 01110010 01110101 01100010 01111001 # "ruby"
XOR expands also:
"%:--!" ^ "woot" # "RUBY!" # # 00100101 00111010 00101101 00101101 00100001 # "%:--!" # ^ 01110111 01101111 01101111 01110100 # "woot" # ======== ======== ======== ======== # 01010010 01010101 01000010 01011001 00100001 # "RUBY!"
AND truncates to the shorter of the two:
"ruby!" & '____' # "ruby" # # 01110010 01110101 01100010 01111001 00100001 # "ruby!" # & 01011111 01011111 01011111 01011111 # "____" # ======== ======== ======== ======== # 01110010 01110101 01100010 01111001 # "ruby"
No known issues. If you find any bugs, please let the author know.
-
Philip Garrett <philip at pastemagazine.com>
Copyright © 2009 Philip Garrett.
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.